Developing apparatus



May 28, 1957 v E. u NTERBERGER DEVELOPING APPARATUS Filed July 16, 1953DEVELOPING APPARATUS Ernst Unterberger, Stuttgart-Bad Cannstatt,Germany,

assigner, by mesme assignments, to Copease Manufacturing Co., Inc., NewYork, N. Y., a corporation of New York Application July 16, 1953, SerialNo. 368,337

Claims priority, application Germany August Z5, 1952 3 Claims. (Cl.95-89) This invention relates to improvements in a device for producingpositive photographic reproductions according to a method in whichexposed negatives together with non-exposed transfer papers are jointlyguided through a developer liquid and are then pressed together by meansof mating rollers. A device of this character is described in U. S.application Serial No. 156,290, filed on April 17, 1950, now Patent No.2,657,618.

In prior devices of this kind, the pressing rollers have been arrangedso that their axles or axes are perpendicular to the feed direction ofthe photographic papers passing therethrough. With such an arrangement,the leading edges of the moistened papers are gripped in full broadsideon entering the roller unit; that is, all portions of the leading edgeof a particular paper are gripped substantially simultaneously.Experience has shown that this construction has a tendency to producewrinkling of the papers and similar disturbances, and that furthermorethe papers after passing through the roller unit tend to stick to thesurfaces of the rollers rather than feeding evenly out of the developingdevice.

It is an object of the present invention to provide an arrangement ofcompressive rollers which minimizes distortion or disturbances in thepapers passing therebetween, and which resists the tendency of thepapers to stick t the roller surfaces. In one embodiment of theinvention disclosed herein, the rollers are arranged such that theiraxles form an angle different from 90 with respect t0 the feed directionof the papers. With such a construction, one corner of the coincidingpapers is gripped first as the papers feed into the roller unit.Experiments have proved that gripping the leading edge corner, ratherthan the full width of the leading edge, causes the entry of the papersinto the roller unit to be substantially more free of disturbances andespecially reduces the tendency of the papers to adhere to the rollersurfaces, the provision of stripper elements or the like normally beingunnecessary.

The guiding means or channels for conveying the papers through thedeveloper liquid to the roller unit may, in the usual manner, be soformed that the papers are horizontally positioned in any sectionperpendicular to the paper feed direction. However, since the papers aregenerally directed upwardly out of the liquid bath before engaging theroller unit, the rollers may be, and preferably are according to theinvention, arranged so that their axles extend in a slightly obliquedownward direction toward the surface of the developer liquid. Thisconstruction affords an additional advantage in that the developerliquid pressed out of the papers passing through the rollers will tendto ow down the outer surfaces of the rollers. The contacting lines orareas of the rollers thereby remain relatively more dry than if they arehorizontally disposed, and the papers emerge from the developing devicein a drier condition than has heretofore been possible.

The gear mechanism ordinarily provided for transmitting rotary motionfrom one pressing roller to the other,

nited States Patent O and which is generally constructed of plasticmaterials, is advantageously arranged at the lower ends of the rollers.This construction provides a continual wetting and lubricating of thesegears by the liquid flowing down the outside surfaces of the rollers,thus prolonging the useful life of the gears.

The oblique position of the rollers does not necessarily result incumbersome or awkward arrangements for the drive motor or hand cranknormally used to impart rotary motion to the rollers. The impellingforce may be transmitted through intermediate bevel gears, the pitchcircle angles of which are so selected that the axis of the drivingbevel gear is directed either vertically or horizontally. With thisarrangement, the usual provisions for a hand crank or a driving motormay readily be made.

Other objects and advantages will be partly pointed out in, and partlyobvious from, the following description taken together with theaccompanying drawings, in which:

Figure l is a fragmentary perspective showing a pair of rollersangularly engaging two sheets of paper; and

Figure 2 is a vertical section of a developing device embodying theinvention.

Figure l illustrates diagrammatically the manner in which an exposednegative 1 together with a transfer paper 2 are jointly fed through aroller unit consisting of two mating compressive rollers 3 and 4. Theaxles or axes of these rollers, according to the invention, extendobliquely with respect to the feed direction of the papers so as to forman angle therewith different than Consequently, as the papers are fedinto the roller unit one corner of the leading edge thereof is firstgripped by the compressive line or area between the rollers 3 and 4, andas the feed continues the remaining portions of the sheets are pressedtogether to induce the transfer of photographic images and to squeezeout excess developer liquid still clinging to the paper.

Secured to the upper end (as viewed in the drawing) of the roller 3 is abevel gear 5, which meshes with a driving bevel gear 6 connected to adrive motor, hand crank, or other prime mover (not shown). Each of thetwo bevel gears 5 and 6 is arranged and constructed so that the sum oftheir pitch circle angles is less than 90; thus the axis 7 of thedriving bevel gear 6 may be arranged to extend vertically (as shown) orhorizontally. With such a gear arrangement, the usual provisions for adrive motor, hand crank, etc., may readily be made without resort toawkward and cumbersome constructions.

Rotary motion of the roller 3 is transmitted to the roller 4 by means ofspur gears 8 and 9, which may be formed of plastic, and which aresecured to the lower ends (as viewed in the drawing) of the respectiveroller axles. Developer liquid pressed out of papers fed through theroller unit tends to flow downwardly along the outer surfaces of therollers and onto these spur gears, thereby providing a wetting action orlubrication which prolongs the usable life of such gears.

Figure 2 shows an embodiment of the invention where` in the compressiverollers 3 and 4 are disposed within a housing 18 formed of any suitablematerial such as plastic. An inner casing 14 is provided to hold anappropriate volume of developer liquid. Openings are arranged in thewalls of the housing i8 and the casing r4 for the insertion andextraction of photographic sheets which are processed through thedevice.

Guiding elements 10, 11, 12 and 13 are arranged so as to form a pathextending from the paper insert opening through the developer liquid andto the mating surfaces of the rollers 3 and d. These guiding elementsmay have any of the shapes known to the art, and need not extendcompletely from the insert opening to the rollers, it being sutiicientto form them so as to reliably guide one corner of each of the papersinto the roller unit.

The remaining portions of the papers are automatically drawn between therollers by the rotary motion thereof, and are pressed together incoinciding position so as to transfer the photographic image onthenegative, developed while passing through the liquid bath, onto the receptive layer of the positive transfer sheet. Y The two inner guidingelements 11 and 12 serve to separate the several sheets one fromanotherV during a portion of the processing through the apparatus. Thelength of these inner guiding elements need not be coextensive with theguide paths, it being primarily necessary only to separate the varioussheets such that there is no interfacial contact until at least one ofthe sheets has become moistened by the developer liquid. By providingtwo inner guide elements, three separate guide channels are therebyformed, thus making it possibile to process a doublesided transfer paperalong ,with two negatives to produce a photomechanical copy havingimages on both sides.

The several papers, after being guided through the developer liquid andpressed `between the rollers 3 and 4 so as to transfer the photographicimages therebetween and to squeeze out excess developer liquidtherefrom, are conveyed through the outlet opening 17 provided in thecasing 18. Guiding wires 15 and 16 direct the pressedtogether papersthrough the opening 17 to a receptacle (not shown).V After anappropriate delay of several seconds or so to allow the photographicimage transfer process to be completed, the papers may be separated fromeach other to produce the desired finished copy.

Although certain specic embodiments of the invention have been shown anddescribed with particularity herein, it is desired to emphasive thatthese are not to be taken as either ylimiting nor exhaustive of theinvention. Rather, they have been included to assist others skilled inthe art to understand the principles of and to practice the invention,it being understood that various modifications may be made, within thescope of the invention as limited by the claims and the prior art, asrequired for particular applications.

I claim: v

1. Apparatus for producing positive photographic reproductions wherein aplurality of paper sheets having photographic emulsion layers on atleast one surface thereof are guided to a set of compressive rollers forpressing said papers together-to transfer photographic images betweensaid emulsion layers and to squeeze out excess developer liquidtherefrom, comprising, in combination, a casing for holding saiddeveloper liquid and having an opening in one portion thereof for theinsertion of photographic sheets, guiding means extending substantiallyfrom said opening to beneath the surface of said developer liquid andupwardly toward the surface of said liquid, and a set of compressiverollers positioned above the liquid to engage photographic sheets guidedthrough and out of said developer liquid, the axes of said rollersforming an angle slightly different from 90 with respect to the feeddirection of said papers as they engage the rollers, and depending in aslight downward direction with respect to the surface of said developerliquid.

2. Apparatus for producing positive photographic reproductions wherein aplurality of paper sheets are guided simultaneously through a developerliquid to a set of compressive rollers for pressing said sheets togetherto transfer photographic images therebetween and to squeeze out excessdeveloper liquid therefrom, comprising, in combination, a casing forholding said developer liquid and having an opening for the insertion ofphotographic sheets, guiding means for controlling the movement ofsheets inserted through said opening and extending substantially fromsaid opening to beneath the surface of said developer liquid andupwardly toward the surface of said liquid, a set of compressive rollerspositioned above the liquid to engage photographic sheets guided throughand out of said developer liquid, the axles of said rollers forming anangle slightly different from with respect to the feed direction of saidpapers as they engage the rollers and disposed so as to form arelatively small angle with respect to the surface of said developerliquid, and driving gear means for said rollers, said gear means beingpositioned at the lower end of said set of rollers whereby excessdeveloperV liquid squeezed out of said sheets will flow thereover toserve as a lubricant for the meshing elements of said gear means.

3. Apparatus for producing positive photographic reproductions wherein aplurality of paper sheets are guided simultaneously through a developerliquid to a set of compressive rollers for pressing said sheets togetherto transfer photographic images therebetween and to squeeze out excessdeveloper liquid therefrom, comprising, in combination, a housing forcontaining said developer liquid and having an opening for the insertionof said papers, guiding means for said paper and forming a pathextending substantially from said opening to beneath the surface of saiddeveloper liquid and upwardly toward the surface of said liquid, tworollers positioned above said liquid and compressively engaged to gripbetween the mating surfaces thereof the leading corner of papers guidedthrough and out of said developer liquid, the axes of said rollersforming an angle slightly different from 90 with respect to the feeddirection of said papers as they engage the rollers and depending in aslight downward direction with respect to the surface of said developerliquid, and bevel gear means for transmitting rotary motion to saidrollers, said bevel gear means including a driving bevel gear, the pitchcircle angle of said bevel gear means being arranged so that the drivingbevel gear axle is disposed in a vertical plane.

References Cited in the le of this patent UNITED STATES PATENTS BelgiumOct. 29, 1952

